1. Calibration of the VA2 B Pal, R Mountain, M Artuso 6/29/2010 Goal: get an absolute calibration of a VA2 channel to measure diamond charge collection

2. Calibration fixture is replaced by single channel fixture

3. Single channel fixture schematic 1.0 pF

4. Channel Gain Channel 141 previously used in diamond measurements

5. Input Bias Nominal gain from specs is 30 mV/fC, which is ½ of the gain we measured in ch 141. Nominal value value Used Vfp-0.2 to 0.5 V-0.4 V Vfs700 mV Pre_Bias100 mV99.8 mV Sha_Bias22 mV22.3 mV i_buf14 mV13.8 mV

6. Gain vs. I_buf

7. To do Calibrate the ADC (have adc/fC now), Check the gain after ADC calibration, Fix the diamond holder, Start studies of “unusual” diamond behavior.